Question "No video signal" with a GTX 950 ?

[Christti]

Sorry for my english

Main PC-PCI express 3.0
CPU-Ryzen 7 3700x
Cooler-be quiet! Pure Rock 2 Silver
Mobo-Asus Guf Gaming x570-plus (wi-fi)
Storage
Windows-SSD PNY CS3030 500GB PCIe NVMe
Games, Files-HDD Seagate 2000GB
GPU-RTX 2080 Aouros Xtreme 8 GB
Ram-Team T-Force Vulcan Z 2x16 gb 3600mhz
PSU-Gigabyte P850GM 850W

Brother's PC-PCI express 2.0
CPU-FX 8350
Cooler-Noctua NH-L12
Mobo-MSI 970 GAMING
Storage
Windows-SSD Adata 120 gb
Games, Files-HDD Seagate 320 gb
GPU-RX 550 2GB
Ram-Kingston 3x4gb 1600 mhz and Samsung 1x4gb 1600mhz
PSU-Game Daemon RPO400 400w

Friend's PC-PCI express 3.0
CPU-I5 4460
Cooler-Stock
Mobo-ASRock B85M Pro3
Storage
Windows, Games, Files-HDD Adata 1tb
GPU-gt710 2gb
Ram-Kingston 2x8gb 2133mhz
PSU-500w PSU

So, I got this GTX 950 Stormx dual Palit 2gb , that was very dirty and full of dust, I tested before on my PC and it was working, I then clean it and still worked on my main PC, then I wanted to install it on my brother's PC , but I did not get any video signal , tried on 1st and 2nd pci express slots, and then I attempted to install it on one of my friend's pc but still no video signal.

The gpu's golden fingers, pci express is a bit rusty, could that be the cause? That It doesn t make perfect contact with the other motherboards because they might have the pci express ports dusty and the gpu's golden fingers, pci express is a bit rusty?

my motherboard is brand new - less than 4 months of use
I changed the thermal paste
I connected the fans on gpu
And ,Yes, I plugged the 6-pin connector on the gpu on all three PCs

edit:On my brother's pc I get 3 beeps after turning on

 

[Christti]

Main PC-PCI express 4.0
CPU-Ryzen 7 3700x
Cooler-be quiet! Pure Rock 2 Silver
Mobo-Asus Guf Gaming x570-plus (wi-fi)
Storage
Windows-SSD PNY CS3030 500GB PCIe NVMe
Games, Files-HDD Seagate 2000GB
GPU-RTX 2080 Aouros Xtreme 8 GB
Ram-Team T-Force Vulcan Z 2x16 gb 3600mhz
PSU-Gigabyte P850GM 850W

Brother's PC-PCI express 2.0
CPU-FX 8350
Cooler-Noctua NH-L12
Mobo-MSI 970 GAMING
Storage
Windows-SSD Adata 120 gb
Games, Files-HDD Seagate 320 gb
GPU-RX 550 2GB
Ram-Kingston 3x4gb 1600 mhz and Samsung 1x4gb 1600mhz
PSU-Game Daemon RPO400 400w

Friend's PC-PCI express 3.0
CPU-I5 4460
Cooler-Stock
Mobo-ASRock B85M Pro3
Storage
Windows, Games, Files-HDD Adata 1tb
GPU-gt710 2gb
Ram-Kingston 2x8gb 2133mhz
PSU-500w PSU

So, I got this GTX 950 Stormx dual Palit 2gb , that was very dirty and full of dust, I tested before on my PC and it was working, I then clean it and still worked on my main PC, then I wanted to install it on my brother's PC , but I did not get any video signal , tried on 1st and 2nd pci express slots, and then I attempted to install it on one of my friend's pc but still no video signal.

The gpu's golden fingers, pci express is a bit rusty, could that be the cause? That It doesn t make perfect contact with the other motherboards because they might have the pci express ports dusty and the gpu's golden fingers, pci express is a bit rusty?

my motherboard is brand new - less than 4 months of use.
I changed the thermal paste. I connected the fans on gpu. And ,Yes, I plugged the 6-pin connector on the gpu on all three PCs.

Edit

1
On my brother's pc I get 3 beeps after turning on.

2
When the gpu is plugged on second pci express port on my pc it seems to get the same issue like the one on my brother's pc. When plugged on the first pci express, It's working perfectly fine.

So at the moment it appears to be a problem with the gpu, probably the pci express connector

3
1 beep an 2 long beeps, on the PCs i tested. I tried to update the firmware, and still nothing, then updated the bios on my brother pc motherboard, and nothing

It only works on my pc on the first pci express port, the white plated pci express 4.0